There have been tremendous advances in the past 10 years or so in the design of high-fidelity audio frequency amplifiers, and some might say that near perfection has already been achieved. However, it seems that with each increment of improvement, new flaws are discovered, often not noticed until previously observed ones have been eliminated.
Perhaps one of the principal remaining areas of imperfection lies in the inability of perhaps most amplifiers to preserve at the output the precise time relationship between sounds of different frequencies which are embodied in the input signal to the amplifier. An excellent example of the problem is that of reproducing the fundamental and all of the harmonically related components coming from a musical instrument without some discrepancy in time of reproduction of the multitude of frequencies present (group delay).
It is the object of this invention to provide an amplifier which reduces the group delay in the time domain and in general improves the quality of reproduction and has a very large phase margin at the output stage.